Vacuum pump



Dec. 1,1925. 1,563,583

W. H. MILLSPAUGH VACUUM PUMP Filed June 28. 1923 `@Illllllllllllllllllllll/` l Patented Dec.: 1, y 1925.

UNITED STATES PATENT OFFICE.

WILLIAM E. MILLSPAUGII, OF SANDUSKY, OHIO, ASSIGNOR TO THE PAPER & TEXTILE MACHINERY COMPANY, OF SANDUSKY, OHIO, A CORPORATION OF OHIO.

v VACUUM PUMP.

,Application and June as, l1923. serial No. 648,218.

To allwhom'itmay concern:` .Be'it known that` I, WILLIAM H. MILLS- PAUGH, a citizenof `the United-States, and a resident of .Sandusky county yof Erie, 'and State of'Ohio, .have invented certain new and useful Improvements in Vacuum Pumps, of which the following is a specification.

This 'invention relates to pumps and particularly to cycloidal vacuum pumps.

Cycloidal vacuum pumps are used largely -in pa er'inillsfor extracting water and other liqui sfrpm the paper sheet. The liquid extracted contains chemicals' such as acids,

alkalis, alum'fandlime water and also frerquently contains grit from the grin'dstones used to grind the pulp. -These chemicals and the grit vinjure the pump elements and casing by erosion and Wear. Bronze parts have been used to overcome the deleterious elfectsof the chemicals, 'but bronze is a comparativelyl soft metal and is easily worn away hy"` the grit.

This invention has for its salient object to provide -a pump particularly adapted for paper mill service and having its parts so constructed that the liquid and foreign matter carried by the liquid will not injure or erode the pump elements or casing.

Further objects of the invention will appear from the following specification taken in connection with the drawings'which form a part of this application, and in which pump constructed in accordance with the invention, and

Fig. 2 is a sectional elevation taken substantially on line 2-2 of Fig. 1. The invention brief-ly described consists of a cycloidal vacuum pump .comprising a casing and impcllers mounted therein, the c0- acting surfaces of the impellers and casing being so constructed that they Will withstand wear and erosion due to the chemicals in` the liquid passing through the pump. It has been found hy experience'fthat these elements can be constructed of ordinary gray cast iron and that if the iron of the castings is not machined, hut the molecular structure of its outer crust or surfaceleft undisturbed, this outer crust or surface Will have the desired characteristics or', in other Words, Will withstand erosion and wear. It has also heen found that if these surfaces are slightly chilled they will have the desired characteristics.-

Referring to the drawing, there. is illus'- trated therein a cycloidal pump having a two-part casing 10, 11, the casing having an inlet opening 12 at the bottom thereof commumcatlng with a chamber 13 to which are connected conduits 14. These conduits may be connected to suction rolls or suction boxes or to driers or other parts of the paper mill apparatus, or to any other form of apparatus Where suction is desired. In the particular embodiment of the invention illustrated, the section 11 of the casing has a discharge shaft 15 provided Witha laterally extending discharge'conduit 16 and a vertically extending discharge conduit 17.

The pump casing has mounted therein cycloidal ilnpellers 20, 21 mounted on shafts 22 and 23., Y f In the embodiment of the invention shown 1n Fig. 1, thepump is mounted on a base 24 having standards 25 and 26 and hearings 27 carried by the standards. The base and standards may becast integral.`

The lpump casing and impellers are pref'- erably formed ofcast iron'A and i articular attention is directedto the fact t at the inner surface 28 of the casing and the outer surfaces 29 ofthe impellers' are not finished or machined,`except for length, but are left v1n undisturbed' or unfinished condition in r l n which. they come from the mold after being Fig. 1 is an elevational View of a cycloidal cast. If desired, these surfaces may be 'chilled but it hasheen found byhactual experience that the surface orcrustformed on of the yliquid will be discharged through the conduit 16 and the air Will rise to the top of the -discharge shaft 15 and Will pass out through the lconduit 17.

The particular' construction of' the pump I isnot material and other forms.of pumps may be used as desired. It is, however, of

primary importance to have the `coactingl vention is capable of modification and that changes in the construction and in the ar rangement ofthe Various cooperating parte may be made without departing from the spirit or scope of the invention, as expressed in the following claims,

What I cla-im is:

1. A cycloidal vacuum pump comprising a casing and impellers therein, said impellers and casing` having cast iron, coacting sur` faces, the skin of said coacting surfaces being undisturbed.

9.. A rotary pump comprising 'a casilw and cast iron ilnpellers therein, the skin o? the enacting surfaces of the impellers being undisturbed.

3. A pump comprising a casing and opcrative relatively movable elements therein,

said casing and elements being formed of cast iron and having the skin of their coacting surfaces undisturbed. y

. 4.' A pump comprising a casing and operative relatively movab e elements therein, said casing and elements being formed of cast iron and havin chilled, coacting surfaces, the skinl of sai surfaces `being undisturbed.

5. A cyeloldal'f vacuum pump comprising a casing and impellers therein, said impellers and casing bein formed of cast 'iron and having undistur ed, chilled, coacting surfaces.

6. A rotary pump comprising acasing, and impellers therein, the coacting surfaces of the impellers being formed of cast iron with its molecular structure undisturbed by being left unfinished.

In witness whereof, I have hereunto set .my hand this 12th day of June, 1923.

WILLIAM H. MILLSPAUGH. 

